>>
>> I think '__metaclass__ = whatever' affects only the creation of
>> classes that
>> would otherwise be old-style classes?
>
> Wrong.
>
> If you set __metaclass__ = type, every class in that module will be
> new-style.
>
> If you set __metaclass__ = MyClass, and MyClass inherits from <type>, every
> class in that module will be new-style and have MyClass as a metaclass.
>
> The usual way to create new-style classes, inheriting from object or
> another
> new-style class, works because if no __metaclass__ is defined, the first
> base class's class is taken as the metaclass.
I was under that impression, too. But this behaves different (py2.4):
---- test.py ----
class meta(type):
def __new__(*args):
print args
return type(*args[1:])
__metaclass__ = meta
class OldStyle:
pass
class NewStyle(object):
#__metaclass__ = meta
pass
---- test.py ----
deets$ python2.4 /tmp/test.py
(<class '__main__.meta'>, 'OldStyle', (), {'__module__': '__main__'})
deets$
I was astonished to see that. Any explanation?
Diez
--
http://mail.python.org/mailman/listinfo/python-list
